blueovalz

I've also read some feedback about failed gears as well. I could not ascertain whether the case split, or the gears failed, so I asked the engineer to comment on that. His experience with building over a 1000 cases was that yes, the case will split, but not before something inside the case gives out first (again, his words). He has seen his gears break at some pretty high power levels, and the resultant damage then forces the gears apart, which then splits the case. His response about the blogs are "you'll find good and bad feedback out there, but I can only go by what I see come through the shop. I rebuild a case for this one guy every 100 or so passes who is running a 3300lb Mustang in the high 9's using a stock case with our gears. He uses a diaphragm clutch, is a skilled driver that is easy on the gears, and has a near perfect set-up...so you run the numbers...he's never had a failure yet". Being this (the BlueOvalZ) is a light car, decent but not excessive (is there such a thing?) horsepower, and with some shifting care, I should be fine. If not, lesson learned to pass onto those who need it. In regards to the set-up: The OEM specs are .002" clearance on the cluster gear. G-force takes the total clearance with no shims (~.110", but should be measured for an actual clearance), and then adds .008" to the actual number for the total shim thickness. This then places the preload on the bearing with a -.008" clearance. Once the case warms to 180º or so, that clearance becomes close to .000" due to the expansion of the aluminum case. He recalled one day when he set the input shaft preload to roughly the same amount, set the case out in the sun to warm up, and an hour later could go out there and free-spin the input shaft as if it had no preload at all.

I got the HD 5th speed gearset today and thought I'd throw out some photos of the OEM as compared to the G-Force set. The HD gear ratio will be .75 while the OEM set was .59 (and my original ones which I had to destroy in order to disassemble the gearbox was .80). To say these are stouter that the OEM gears is an understatement!

Can you tell me what the specs are on those aluminum bushings (the ones that fit into the rod ends), and where you sourced them?

I don't think you're nuts. What I would do though is get a couple of the bigger rings, and a couple of smaller rings just to experiment with. I would take one of the smaller rings and install it, then remove it, and THEN measure the ID. if it is larger than when you put it on (by a reasonable amount???), then it's been stretched in the process of installing it (and ruined in my opinion), and you may want to return to a larger ID clip. From the looks of your photos, it appears the larger ID OEM clip is not stretched (based upon the spacing of the gap). IF the measurement is the same after installing and removal of the tighter clip, then you know you've not ruined the spring tension in the ring, and you're good to go.

That's pretty linear all right!

Ahhhh, a hybrider that thinks like a hybrider. Sounds like we'll see your handywork soon enough.

I personally would not use a set of washers for several reasons: 1) A stack of washers allows more movement over a properly designed spacer should the bolts holding the rotor into place become loose (would or should they ever do this is another issue). 2) This one is most important to me. I've taken washers and measured their thickness, and even SAE washers sometimes show some variance in thickness. Unless you have measured the stack of washers to ensure each bolt has an identical value for the width of the washer stack, you're placing some degree of runout into the rotor when it all gets installed. 3) The spacer allows full contact between the rotor and the hub when it's all assembled. Washers offer a smaller contact area between the two. Almost like you would be "cantilevering" the rotor out from the hub.

Can you post a graph? I'm curious how the angle of the CA effects the ratio (e.g. is the ratio different at full droop verses full compression). Is this number an average thoughout the entire range?

I attempted to pick and choose what I needed. I found out I needed more shorter radius bends (2.5-4") than I thought, and fewer 5-8" bends than I thought. I wanted to do the 4-1 typical header design, but with the wide road pan, I'd be right on the pan, and the T/C bushings, so Tri-Y was my remedy.

I shudder to think of what I eventually spent. Let's see...about $330 for tubes (yes, I had some extra, but not much), $110 for the flanges, $65 for the collectors (if that's what you want to call them), and $260 for the JetHot (includes shipping and all), so that is $765 EEE...GAD!!! Jeeze, I'm glad I wasn't keeping track of all this at the time I did it. And that doesn't even cover the time, grinding discs, and welding rods. I've been meaning to get some photos out due to another request, so here they are: These are the passenger side headers: This is hard to make out but the tube comes inside of the frame rail by about 3/4" The driver's side headers: It looks like a header flange up against the frame rail, but that is the tube's reflection in the paint. Another hard to make out photo. The tubes curve down an back in toward the engine about 1/2" (blistering paint I'm sure) above the frame rail in order to clear the steering rod. The "tab" on the left is not a header part but instead the pigtail for the starter which is part of the engine plate.

I did the MIG thing with my first set of headers, and it doesn't look nearly as nice as this TIG set does. Material?...Nothing exotic or unusual. Simply bought some mandrel bent tubing (Hooker I think) and went after it. You won't be saving any money though. I spent as much on mine as a nice set of custom made headers, but then, NOBODY makes custom headers for the SBF in a Z, and if they do, it's got to be a one size fits all. So in the long run, it was still worth the expense and time to do this. And best of all (need I say this?), it was something home made and not bought outright.

Would it be correct to say that there is no slippage (CLSD is not wearing) in straight line use as well (while gripping and assuming the tires are the same height and pressure)?

Dr, From what I can observe looking at my gears (this is a guess), the OEM 5th gear set has a 40º to 45º degree cut (yea, that's a lot). The 5th gear design is intended for quiet, highway oriented operation in which the powerplant RPM is well below the peak torque. Install a high ratio differential (mine is 4.11), added torque, especially down low, and you start having problems. Perhaps you can answer this concern I also have about the OEM gear ratio or design, and that is the really tiny (relatively speaking) driven gear diameter. I'm wondering if this plays into the separation forces, or losses between the two gears as well. It would seem to me the smaller the gear diameter, the more lateral force imparted in the gear-shaft. Is this true or insignificant? All of this is why I threw in the towel and purchased the G-force 5th gear-set last week. This set has a much straighter cut on the gears. When I talked to their engineer, he said the gear will whine somewhat because of this design, but said as long as you've also got the gear cluster plate installed, separation of the gears will be reduced and that it will no longer be the "weak" gear for those using this gear as intended (road or track events). It is a .75 ratio, which is at least better than my current .80 ratio (70 MPH drops from 3000 to 2800 RPM). He also reiterated that they alway build their cases with preload on the bearings to allow for the expansion of the aluminum case (more so than the steel shafts and gears) as opposed to the several thousanths of clearance set by the manufacturer (his words). Listening to him talk about this gave me the impression that this was almost as important as purchasing all the nice tough gears.

Please, no tears....I just purchased an '88 CLSD with axles from a 300ZX Turbo for $90 from a pick-and-pull (3.70 ratio).

The main advantage of doing this with the Techno Toy parts is that they appear to be simply thick steel plates welded together to form the strut assembly. If you were serious about this idea, I'd see if you could get the parts and pieces from that vendor prior to the weldup and position the main plate (the plate holding the hub) one inch rearward, and weld it yourself. Alignment would be the big concern if you did this (lower control arm pickup points are parallel to the main plate and perpindicular to the tube, as well as kingpin inclination).

I used to ponder this as well. My thoughts were to search for a head that had the Ford bore spacing rather than the bore diameter, but those offer even fewer options from what I saw.

Mine worked (and I did have a couple of the more narrow ones, but I didn't drill holes in them) pretty well on anything larger than a 3" radius. When the radius dropped to 2.5 or less, positioning of the clamp required more time and skill in keeping the joint held together.

Hmmm...Okay, I won't tell you I made them... Sorry, I made them. They are 1/8" aluminum. I used a round template and a small filament light bulb to produce a round shadow (visually from directly in back of the car), which if viewed from a perpendicular angle was in reality an oblong hole, to mark the outline. Then I transferred that to the aluminum plate. THEN I had to stretch the plate by hammering on it until it fit the compound curve contour of the rear panel. I was kinda a pain, but the final product made it well worth it.

Something I found out a while back is the installation of these rings is as important as the size. Using a ring that has an initial tight fit may be for not if it is spread beyond its yield strength upon intallation in the attempt to get it over the splines. I thought I'd find a clip one size smaller for a better grip, only to find out that it had to be stretched beyond its yield strength in order to get it over the shaft. As a result, once installed, it has less grip than the larger ring had in the first place. My lesson; spread it only far enough to slip it over the shaft, and no more.

This is the groove the retaining ring sit in. Look at the 4th and 5th splines from the TOP. Looks like shadows but those are the only slight wear marks produced by the failure. They are slightly polished looking and I don't think the material really deformed any. These photos are great. So...are you saying the right edge of this groove is NOT rounded/ramped as a result of the snap ring slipping out? In particular, the upper most spline in this photo looks like trouble. To me it looks ramped, like this → |___/

The ones I used were 1/2" wide. They were old, so I don't know if its just because they are old, or that the new ones are more narrow.

gijonas took the words right out of my mouth. This 4" hole is a little larger, but there is no reason it couldn't be smaller.

To add to the "hose clamp" discussion, I also used hose clamps to hold the various bends together after cutting them. If tightened well, I could hold 3 separate joints together using hose clamps placed directly over the tubing joints. The larger the bend radius, the better this worked. The short-radius bends caused a little problem with this (e.g up next to the flange stubs), but still held the tubes together. This way I was able to have all four primary tubes adjustable as I built the header. The use of the clamps then allowed me to tweak, correct, rotate, and shift the tubes around a small amount to perfect the close fit. Then I drilled two 1/4" holes in the hose clamps and used that hole as a "port" for tacking the tube sections together. Once the tacking was done, I removed the clamp and TIG'd the rest of the weld.

I'm too lazy to reset the date on the camera after replacing the battery, but you're not the only one to bring that up. I guess it's time update it. The jig was two 2x4s bolted to the crossmember, and to the rear plate as the engine sat on the engine stand. I used some thinwall conduit as the steering rod on the jig. On the below photo, you barely see the conduit angled up as it goes rearward over the top of the 2x4.

The jig I built to fabricate these headers out of the car worked right-on. The headers went in (very tight, so that part was not easy, nor was it expected to be) fine, and surprisingly, all clearances were exactly as was on the jig. The driver's side header Passenger side header